Element for compressing or expanding gas and method for controlling the same

Abstract

The present application relates to an element for compressing or expanding gas and a method for controlling the same. The element comprises: a rigid housing (2) containing an internal chamber; a rotor (3a, 3b) located in the internal chamber, the rotor comprising a rotor shaft (4a, 4b); one or more bearings (7), the rotor shaft (4a, 4b) being supported by the bearings, the rotor (3a, 3b) and its rotor shaft (4a, 4b) being rotatably mounted relative to the housing (2) by means of the bearings (7); wherein the rotor (3a, 3b) is mounted with one or more gaps relative to a wall (5) of the internal chamber; and is characterized in that the element (1) is provided with a separate yielding member (10), the position of which relative to the housing (2) is adjustable so as to act on at least one gap, the separate yielding member not being directly attached to the rotor (3a, 3b).

Description

Technical Field

[0001] The present invention relates to an element for compressing or expanding a gas and a method of controlling the element.

[0002] More specifically, the invention relates to an element having a rigid housing containing an internal chamber and a rotor located in the internal chamber, the rotor being mounted with one or more gaps relative to the walls of the internal chamber, and the element being provided with a separate yielding member whose position is adjustable relative to the housing so as to be able to act on at least one gap. Background Art

[0003] Elements are known from the prior art in which a gas can be compressed or expanded between an input and an output of the element by the rotation of one or more rotors in a housing, wherein the interior of the housing is divided by the rotors into a plurality of substantially mutually enclosed operating chambers which are at different pressures and which are moved from the input to the output by the rotation of the rotors.

[0004] In this case, the rotor is mounted in the inner chamber with one or more gaps relative to the walls of the inner chamber and / or relative to each other, in order to avoid mechanical contact between the rotor and the walls of the inner chamber and / or between the rotors themselves. After all, such mechanical contact could lead to excessive mechanical stress on the rotor or the housing, which could lead to damage to the components.

[0005] On the one hand, these gaps must not be too large in order to avoid excessive leakage flows between the operating chambers, which would reduce the efficiency of the element.

[0006] On the other hand, the gap cannot always be or remain reduced to the required minimum due to the following reasons:

[0007] - the manufacturing tolerances of the components of the element;

[0008] - thermal expansion of the components of the element during its operation;

[0009] - vibration behavior of the rotor during operation of the element;

[0010] - mechanical loading of the components of the element during its operation due to compressive forces on one or more rotors, combined with excessive bearing compression and rotor bending;

[0011] - wear or dirt deposits on the surfaces of the components of the element over time.

[0012] In this context, "during operation of the element" means that the element is in an operating state in which the rotor of the element rotates.

[0013] Furthermore, the required gap size depends on the different operating conditions of the components.

[0014] Once the component is started, when the component temperature is relatively low compared to nominal operating conditions, the relatively large gap can provide mechanical stability to the component.

[0015] In elements operating under free-running conditions (where the element still rotates but does not have to output or consume almost no power to the gas) a relatively large clearance is also required to limit this output or consumed power compared to elements under full load conditions.

[0016] Large clearances are also required to provide mechanical stability to components operating in speed ranges where increased vibrations are caused at the resonant frequencies of the rotor and / or bearings.

[0017] Under nominal operating conditions, when the element temperature is relatively high relative to the temperature during element startup, the relatively small clearance can again produce high compression efficiency.

[0018] This creates a need for a system that actively controls the clearances in the component during operation.

[0019] US Patent No. 10539137B2 describes a compressor element comprising:

[0020] - a housing with a chamber;

[0021] - a helical rotor configured to be mounted in the bore with a rotor clearance during operation of the compressor element;

[0022] - an adjustable bearing, for example a magnetic bearing, in which the helical rotor is mounted; and

[0023] - a controller configured to control the adjustable bearing during operation of the compressor element such that the adjustable bearing moves the rotor in a manner that reduces or increases the rotor clearance.

[0024] However, bearings, in particular magnetic bearings, are generally less durable components of compressor elements and are easily susceptible to disturbances during operation due to excessive mechanical loads and the resulting possible mutual displacements of the individual bearing components.

[0025] More specifically, a particular disadvantage of magnetic bearings is their very low stiffness. Vibrations in the element caused by gas pulsations during compression or expansion are only slightly damped in the magnetic bearing. In the event of vibrations in the element, this can lead to noticeable and sudden deviations between the components of the magnetic bearing and thus within the element itself.

[0026] Therefore, it is not advisable to control the clearances in elements for compressing or expanding gases based on the relative positions of the bearing components. Summary of the Invention

[0027] The object of the present invention is to provide a solution to at least one of the above-mentioned and / or other drawbacks by providing a robust yet directed and flexible control of one or more gaps in an element for compressing or expanding a gas.

[0028] To this end, the invention relates to an element for compressing or expanding a gas, comprising:

[0029] - a rigid housing containing an interior chamber;

[0030] - a rotor located in the inner chamber, the rotor including a rotor shaft;

[0031] one or more bearings, wherein the rotor shaft of the rotor is supported by the bearings, by means of which the rotor and its rotor shaft are rotatably mounted relative to the housing,

[0032] wherein the rotor is mounted with one or more gaps relative to the wall of the inner chamber,

[0033] Its characteristics are:

[0034] The element is provided with a separate yielding member, which comprises:

[0035] - a fixed portion having a fixed or substantially fixed position relative to the housing; and

[0036] a position-adjustable portion, the position of which is adjustable relative to the housing, the position-adjustable portion being configured to act on at least one gap,

[0037] The separate yielding member is not directly attached to the rotor.

[0038] In this context, a "rigid housing" is defined as a housing in which, under operating conditions of the component, the deviation of one point of the housing relative to other points of the housing remains limited to within 10 μm when the housing is deformed.

[0039] In this context, the rotor shaft being "supported by bearings" in one or more bearings means that the rotor shaft is rigidly fixed both axially and radially relative to a co-rotating portion of the one or more bearings that co-rotates relative to the rotor shaft.

[0040] A "yielding member" as used herein is a member having a surface on which a point under the influence of a force can move at least 30 μm in the direction of the force relative to its original position relative to the shell when the force is not applied to the surface, but the member will not undergo plastic deformation under these circumstances.

[0041] The term "separate yielding member" herein means that the yielding member is not manufactured integrally with the housing. In other words, the separate yielding member does not constitute a part of the housing and can be separately installed in or removed from the element.

[0042] In this context, “a fixed portion having a fixed or substantially fixed position relative to the housing” means that any displacement of the fixed portion relative to the housing has no significant effect on the one or more gaps.

[0043] Herein, “a position-adjustable portion whose position is adjustable relative to the housing” means that at least one point of the position-adjustable portion can be displaced relative to a point of the housing.

[0044] An advantage is that by providing separate yielding members in a rigid shell, a more localized and directed action on the gap can be achieved than if the entire shell were implemented yieldingly.

[0045] Realizing the separate yielding member independently of the shell also makes it easy to combine the separate yielding member and the shell made of different materials with each other, or to manufacture the separate yielding member and the shell based on different manufacturing techniques.

[0046] By acting on the gap, an optimum balance can be established between avoiding excessive leakage flows between the rotor and the inner chamber wall in the element on the one hand and avoiding high mechanical stresses between the rotor and the housing at the inner chamber wall on the other hand.

[0047] Furthermore, a separate yielding member allows acting on the gap between the rotor and the inner chamber wall, without having to act directly on the operation of the bearing or the relative position of the components in the bearing.

[0048] Another advantage is that the position of the individual yielding members relative to the housing can be adjusted without having to take into account the effects of rotor rotation on the individual yielding members during operation of the element, such as centrifugal forces acting on the individual yielding members.

[0049] In a preferred embodiment of the element, the bearing of the one or more bearings is integrally movably arranged relative to the housing; the position-adjustable portion is configured to contact a non-rotating portion of the bearing that does not rotate relative to the housing and exert a force on the non-rotating portion.

[0050] In this way, the bearing as a whole together with the rotor is displaced relative to the housing.

[0051] In a preferred embodiment of the element described below, the position-adjustable portion is configured to be moved in or out, respectively, relative to at least one gap.

[0052] In this way, at least one gap is sealed or opened by the position-adjustable portion.

[0053] In the following preferred embodiment of the present invention, the element includes a plurality of rotors, which are installed with gaps between each other so that a plurality of substantially mutually enclosed operating chambers are formed in the inner chamber by the rotors, and the position-adjustable portion is configured to change the size of the gaps between the rotors.

[0054] The advantage in this case is that excessive mechanical stresses and / or leakage flows between the rotors can also be avoided, so that the clearance can be set optimally for each operating condition of the elements.

[0055] In the following preferred embodiment of the element according to the invention, the separate yielding member comprises a radial rotor positioner configured to enable radial displacement of the rotor and the housing relative to each other with respect to the rotor axis.

[0056] In this way, the radial play between the rotor and the inner chamber wall and / or between the rotors can be increased or reduced in the element depending on the rotor axis.

[0057] In a more preferred embodiment of the element according to the invention, at least one of the bearings is a radial bearing which is arranged integrally movably relative to the housing; and the radial rotor positioner comprises a first shape-variable form configured to contact a non-rotating portion of the radial bearing which does not rotate relative to the housing and to exert a force on the non-rotating portion.

[0058] In this way, the radial bearing as a whole together with the rotor is displaced relative to the housing.

[0059] In the following preferred embodiment of the element according to the invention, the separate yielding member comprises an axial rotor positioner configured to enable the rotor and the housing to be axially movable relative to each other with respect to the rotor shaft.

[0060] In this way, the axial gap between the rotor and the inner chamber wall in the element, depending on the rotor axis, can be increased or reduced.

[0061] If the element comprises a plurality of rotors, the size of the mutual gaps between the rotors can be varied by axially displacing the rotor shaft of one of the plurality of rotors relative to the housing.

[0062] In a more preferred embodiment of the element according to the invention, at least one of the bearings is an axial bearing which is arranged integrally movably relative to the housing; and the axial rotor positioner comprises a second shape-variable body which is configured to contact a non-rotating portion of the axial bearing which does not rotate relative to the housing and to exert a force on the non-rotating portion.

[0063] In this way, the axial bearing as a whole together with the rotor is displaced relative to the housing.

[0064] In the following preferred embodiment of the element according to the invention, the separate yielding member comprises a radially adjustable ring body surrounding the rotor shaft, the outer periphery of the radially adjustable ring body being fixedly attached relative to the housing, and the radially adjustable ring body being configured such that a radially outer inner radius of the radially adjustable ring body, dependent on the rotor shaft, can be varied in size.

[0065] By reducing or increasing the outer inner radius of the radially adjustable ring, a radial gap in the element between the rotor shaft and the housing, depending on the rotor shaft, can be sealed or opened, respectively, by the radially adjustable ring.

[0066] In the following preferred embodiment of the element according to the invention, the inner chamber comprises a bore according to the direction of the rotor axis.

[0067] In a more preferred embodiment of the element, the separate yielding member comprises an axially adjustable body attached to the end face of the bore, the axially adjustable body having a first specific deformable shape, the first specific deformable shape being configured to be able to seal or open an axial gap between the rotor and the end face depending on the rotor axis, so that the first operating chamber in the inner chamber can be isolated from or fluidically connected to the second operating chamber in the inner chamber, respectively.

[0068] In the following more preferred embodiment of the element, the separate yielding member includes a radially adjustable body attached to the rotating surface of the cavity, the radially adjustable body having a second specific deformable shape, and the second specific deformable shape is configured to be able to seal or open a radial gap between the rotor and the rotating surface depending on the rotor axis, so that the third operating chamber in the inner chamber can be isolated from or fluidically connected to the fourth operating chamber in the inner chamber, respectively.

[0069] In the following preferred embodiments of the present invention, the element comprises mechanical, hydraulic and / or pneumatic means for adjusting the position of the position-adjustable portion relative to the housing.

[0070] The advantage is that such mechanical, hydraulic and / or pneumatic devices are mechanically durable and that the yielding member whose position is adjusted by such mechanical, hydraulic and / or pneumatic devices can withstand higher mechanical loads, such as the yielding member whose position is adjusted by (electro)magnetic devices in the case of magnetic bearings.

[0071] Another advantage is that the movement of a mechanical device or the pressure used to drive a hydraulic or pneumatic device can be precisely controlled, more precisely in all respects than, for example, controlling the temperature used to drive a thermal device (which would cause thermal expansion or contraction of the position-adjustable portion of a separate yielding member).

[0072] In a preferred embodiment of the present invention described below, the element includes a controller for driving the position-adjustable portion.

[0073] With the help of such a controller, one or more gaps can be acted upon automatically without the operator having to manually intervene in the elements.

[0074] The invention relates to a device for compressing or expanding a gas, comprising an element according to one of the above-described embodiments.

[0075] It goes without saying that such an arrangement offers the same advantages as the element according to one of the preceding embodiments.

[0076] Furthermore, the invention also relates to a separate yielding member for use in an element according to one of the above-described embodiments or in an above-described device.

[0077] Furthermore, the present invention relates to a method for controlling an element for compressing or expanding a gas, the element comprising:

[0078] - a rigid housing containing an interior chamber;

[0079] - a rotor located in the inner chamber, the rotor including a rotor shaft;

[0080] one or more bearings, wherein the rotor shaft of the rotor is supported by the bearings, by means of which the rotor and its rotor shaft are rotatably mounted relative to the housing,

[0081] wherein the rotor is mounted with one or more gaps relative to the wall of the inner chamber,

[0082] It is characterized by:

[0083] The method comprises the steps of acting on at least one gap by adjusting the position of a position-adjustable portion of a separate yielding member of the element relative to the housing,

[0084] wherein the fixed portion of the individual yielding member is maintained in a fixed or substantially fixed position relative to the housing, and

[0085] Therein, the separate yielding member is not directly attached to the rotor.

[0086] It goes without saying that such an arrangement offers the same advantages as the element according to one of the preceding embodiments.

[0087] In a preferred embodiment of the method according to the invention, at least one of said one or more gaps is controlled while the element is in operation.

[0088] The advantage in this case is that the clearance can be controlled during operation based on the operating conditions of the element and thus an optimum balance can be set between avoiding excessive leakage flows in the element on the one hand and avoiding high mechanical stresses between the rotor and the housing at the inner chamber wall on the other hand. BRIEF DESCRIPTION OF THE DRAWINGS

[0089] In order to better illustrate the characteristics of the present invention, some preferred embodiments of the element for compressing or expanding gas according to the present invention will be described below by way of non-limiting examples with reference to the accompanying drawings, in which:

[0090] Figure 1 shows a cross section of a first embodiment of an element according to the invention;

[0091] Figure 2 Shown in more detail Figure 1 a portion of a first separate yielding member in an element;

[0092] Figure 3 shows a cross section of a second alternative embodiment of an element according to the invention;

[0093] Figure 4 Shown in more detail Figure 3 a cross-sectional view of a second separate yielding member in the element;

[0094] Figure 5 shows a cross section of a third alternative embodiment of an element according to the invention;

[0095] Figure 6 In more detail, Figure 5 The part marked as F6 is shown in a cross-sectional view. Figure 5 a third individual yielding member in the element;

[0096] Figure 7 shows a cross section of a fourth alternative embodiment of an element according to the invention;

[0097] Figure 8 In more detail, Figure 7 The part marked as F8 is shown in a cross-sectional view. Figure 7 a fourth separate yielding member in the element;

[0098] Figure 9 shows a cross section of a fifth alternative embodiment of an element according to the invention;

[0099] Figure 10 In more detail, Figure 9 The portion marked F10 is shown in cross-section. Figure 9 a fifth individual yielding member in the element;

[0100] Figure 11 A sixth alternative embodiment of an element according to the invention is shown in cross section. DETAILED DESCRIPTION

[0101] The terminology used is intended only to describe the preferred embodiments by way of example, and should not be construed as limiting the scope of protection defined in the claims.

[0102] Terms preceding the singular form "a", "an" or "the" may also include the plural form of these terms.

[0103] Although the terms "first," "second," "third," "fourth," or "fifth" are used below to refer to different shape-adaptable bodies, cavities, pressures, or operating chambers, these shape-adaptable bodies, cavities, pressures, or operating chambers are not limited by these terms. These terms are at most used to distinguish the types of shape-adaptable bodies, cavities, pressures, or operating chambers. When terms such as "first," "second," "third," "fourth," or "fifth" are used below, these terms do not imply any particular order or sequence. Thus, a first shape-adaptable body, cavity, pressure, or operating chamber can easily be designated as, for example, a second or third shape-adaptable body, cavity, pressure, or operating chamber, without exceeding the scope of the exemplary embodiments. It should also be mentioned that there can be multiple first, second, third, fourth, or fifth shape-adaptable bodies, cavities, pressures, or operating chambers.

[0104] Figure 1 An element 1 according to the invention for compressing a gas is shown.

[0105] The element 1 comprises a rigid housing 2 containing an internal chamber; in this case, the housing 2 is realized by several parts that can be easily assembled or disassembled with one another in order to place or remove the rotors 3a, 3b respectively in or from the internal chamber.

[0106] exist Figure 1 In the element 1 in FIG. 1 , two rotors 3 a, 3 b are located in an inner chamber, each having a rotor shaft 4 a, 4 b. In this example, the two rotors 3 a, 3 b are realized as two intermeshing helical rotors, which are mounted with clearances relative to the wall 5 of the inner chamber and relative to each other, so that the inner chamber is subdivided by the helical rotors into a plurality of operating chambers which are closed to each other except for the clearances.

[0107] By the rotation of the rotors 3a, 3b, gas will be sucked from the inlet 6 into the operating chamber connected to the inlet 6 in the inner chamber. By further rotation of the rotors 3a, 3b, the operating chamber will be axially moved away from the inlet 6 relative to the rotor shafts 4a, 4b and closed relative to the inlet 6. Thereafter, as the rotors 3a, 3b further rotate, the gas sucked into the operating chamber will be compressed.

[0108] This means that in each operating chamber which follows from the inlet 6 in the axial direction relative to the rotor axis 4 a, 4 b, the gas drawn into the interior is compressed with increasing pressure.

[0109] Due to the pressure differences between the successive operating chambers, a gas leakage flow occurs via the gap in the direction of the inlet 6 .

[0110] The rotor shafts 4 a , 4 b of the rotors 3 a , 3 b are supported in bearings 7 , and the rotors 3 a , 3 b and their rotor shafts 4 a , 4 b are rotatably mounted relative to the housing 2 via the bearings 7 .

[0111] Bearing 7 can be realized as:

[0112] - radial bearings 8 capable of absorbing radial mechanical loads relative to the rotor shafts 4a, 4b; and / or

[0113] - Axial bearings 9 capable of absorbing axial mechanical loads relative to the rotor shafts 4a, 4b.

[0114] although Figure 1 The bearings 7 in FIG. 4 are located around the ends of the rotor shafts 4 a, 4 b furthest from the element inlet 6, but it is not excluded within the scope of the invention that the bearings 7 are located at the ends of the rotor shafts 4 a, 4 b at the inlet 6.

[0115] Without any preference, element 1 is in this example an oil-injected compressor element.

[0116] It is not excluded or opposed within the scope of the invention that the element is a compressor element without oil filling in the inner chamber, wherein the rotation of the rotors in the inner chamber is synchronized, for example by means of mutually meshing gears on the rotor shafts of these rotors.

[0117] It is also not excluded from the scope of the invention that the element is an element for expanding gas.

[0118] In order to act on the at least one gap, the housing 2 is provided with at least one separate yielding member 10 , which is positionally adjustable relative to the housing 2 .

[0119] “Acting on at least one gap” means that the minimum cross-section of the gap between the rotors 3a, 3b and the wall 5 of the inner chamber or between the rotors 3a, 3b is reduced or increased by means of a separate yielding member 10; and / or

[0120] - Sealed or open.

[0121] exist Figure 1 In the case of the element 1 in FIG. 1 , the separate yielding member 10 is realized as a radial rotor positioner 11 which enables radial displacement of the rotors 3 a, 3 b and the housing 2 relative to each other according to the rotor shafts 4 a, 4 b.

[0122] Figure 2 A more detailed and specific example of a portion of such a radial rotor positioner 11 is shown.

[0123] The radial rotor positioner 11 comprises a first shape-variable body 12 having a through-hole 13 .

[0124] In the through hole 13 , a non-rotating portion of one of the bearings 7 (in this case, the radial bearing 8 ) that does not rotate relative to the housing should be securely fixed.

[0125] Furthermore, the first shape-variable form 12 encloses a plurality of first cavities 14, which are closed or substantially closed relative to the interior chamber, each of which is at a separate first pressure, wherein, in a plane perpendicular to the rotor axes 4a, 4b, a first one 14a of the first cavities 14 is located directly opposite at least one second one 14b of the first cavities 14 relative to the rotor axes 4a, 4b.

[0126] The first shape-variable body 12 is configured and controlled so that: when the first pressure in the first one 14a of the first cavities 14 increases,

[0127] - the volume of the first 14a of the first cavities 14 increases; and

[0128] - a first pressure in the at least one second 14b of the first cavity 14 is reduced so that the volume of the at least one second 14b of the first cavity 14 is reduced,

[0129] The radial bearing 8 is thereby displaced together with the rotors 3 a , 3 b relative to the housing 2 in the radial direction relative to the rotor shafts 4 a , 4 b towards at least one second one 14 b of the first cavity 14 .

[0130] More specifically, the radial rotor positioner 11 includes an outer ring 15 , an inner ring 16 , and a space between the outer ring 15 and the inner ring 16 that is closed or substantially closed with respect to an inner chamber.

[0131] In this example, the outer ring 15 is fixedly attached relative to the housing 2 , for example by a flange 15 a being part of the outer ring 15 , while the inner ring 16 is fixedly attached to a non-rotating portion of the radial bearing 8 that does not rotate relative to the housing 2 .

[0132] It is not excluded within the scope of the invention that in this case the outer ring 15 is fixedly attached to a non-rotating portion of the radial bearing 8 that does not rotate relative to the housing 2 , while the inner ring 16 is fixedly attached to the housing 2 .

[0133] In this example, the radial rotor positioner 11 has a spring structure 17 in the space between the outer ring 15 and the inner ring 16, which is connected to the outer ring 15 on the one hand and to the inner ring 16 on the other hand. In this way, the aforementioned space is subdivided into a plurality of mutually separated, substantially ring-segment-shaped compartments, each of which serves as one of the first cavities 14.

[0134] Each compartment can be provided with a connection point ( Figure 1 or Figure 2 ), is used to supply or exhaust the working fluid to increase or decrease the initial pressure in each compartment respectively.

[0135] Figure 2 The radial rotor positioner portion shown also includes a disc-shaped sealing plate ( Figure 2 (not shown), the sealing plate is axially attached to both sides of the outer ring 15 according to the rotor shafts 4a, 4b, and is used to seal and isolate the space between the outer ring 15 and the inner ring 16 axially relative to the inner chamber according to the rotor shafts 4a, 4b.

[0136] Figure 3 A second alternative embodiment of an element 1 according to the invention is shown.

[0137] exist Figure 3 In the case of the element 1 in FIG. 1 , the separate yielding member 10 is realized as an axial rotor positioner 18 which enables the rotors 3 a, 3 b and the housing 2 to be displaced axially relative to each other according to the rotor shafts 4 a, 4 b.

[0138] The axial rotor positioner 18 is located between the housing 2 and a non-rotating portion of at least one bearing 7 (in this case, the axial bearing 9 ) that does not rotate relative to the housing 2 .

[0139] Figure 4 A more detailed and specific example of such an axial rotor positioner 18 is shown.

[0140] The axial rotor positioner 18 comprises a second shape-variable form 19 which encloses a second cavity 20 which is closed or substantially closed with respect to the interior chamber.

[0141] In this example, the second shape-variable body 19 is constructed and controlled such that its axial dimension relative to the rotor shafts 4a, 4b is increased or decreased by increasing or decreasing the second pressure in the second cavity 20, respectively.

[0142] To this end, the second shape-variable body 19 may be provided with a connection point 35 for supplying or draining the working fluid to increase or decrease the second pressure in the second cavity 20 , respectively.

[0143] By increasing the axial size of the second shape-variable body 19, the second shape-variable body 19 displaces the axial bearing 9 together with the rotors 3a, 3b in the axial direction relative to the housing 2 according to the rotor shafts 4a, 4b. Once the axial size of the second shape-variable body 19 is reduced again, the axial bearing 9 and the rotors 3a, 3b can return to their original positions in the axial direction according to the rotor shafts 4a, 4b.

[0144] In this way, the axial clearance between the rotors 3a, 3b and the housing 2 depending on the rotor shafts 4a, 4b can be increased or decreased.

[0145] Figure 5 A third alternative embodiment of an element 1 according to the invention is shown.

[0146] exist Figure 5 In the case of the element 1 in FIG. 1 , the separate yielding member 10 is implemented as a radially adjustable ring 21 surrounding the rotor shafts 4 a, 4 b. The outer periphery 22 of the radially adjustable ring 21 is fixedly attached relative to the housing 2. Furthermore, the radially adjustable ring 21 is configured such that a radially outer inner radius 23 of the radially adjustable ring 21, which is determined by the rotor shafts 4 a, 4 b, can be varied in size.

[0147] "Radially outer inner radius of the radially adjustable ring relative to the rotor axis" means the linear radius

[0148] - located in a plane perpendicular to the rotor axes 4a, 4b;

[0149] - Its first end point is located on the rotor shaft 4a, 4b;

[0150] - its second end point is a point of the radially adjustable ring 21; and

[0151] Every point between its first and second end points is not a point of the radially adjustable ring body 21 .

[0152] Figure 6 A more detailed and specific example of the radially adjustable ring 21 is shown.

[0153] The radially adjustable ring body 21 comprises an annular third shape-variable form 24 which encloses a third cavity 25 which is closed or substantially closed with respect to the interior chamber.

[0154] The third shape variant 24 is configured such that the radially outer inner radius 23 according to the rotor shaft 4 a , 4 b is reduced or increased by increasing or decreasing the third pressure in the third cavity 25 , respectively.

[0155] To this end, the third shape-variable body 24 may be provided with a connection point ( Figure 5 or Figure 6 ), for supplying or exhausting the working fluid to increase or decrease the third pressure in the third cavity 25, respectively.

[0156] By reducing the radially outer inner radius 23, the radially adjustable ring body 21 expands radially inwardly around the rotor shafts 4a, 4b in accordance with the rotor shafts 4a, 4b. Once the radially outer inner radius 23 is increased again, the radial distance between the radially adjustable ring body 21 and the rotor shafts 4a, 4b in accordance with the rotor shafts 4a, 4b increases again.

[0157] In this way, the radial gap between the rotor shafts 4a, 4b and the housing 2 can be increased or decreased accordingly depending on the rotor shafts 4a, 4b.

[0158] Figure 7A fourth alternative embodiment of an element 1 according to the invention is shown.

[0159] The inner chamber comprises a bore 26 according to the orientation of the rotor shafts 4a, 4b.

[0160] exist Figure 7 In the case of the element 1 in , the separate yielding member 10 is embodied as an axially adjustable body 27 attached to the end face 28 of the bore 26 .

[0161] The axially adjustable body 27 has a first specific deformable shape, which is configured to seal or open the axial gap between the rotors 3a, 3b and the end surface 28 according to the rotor shafts 4a, 4b, so that the first operating chamber in the inner chamber can be isolated from or fluidically connected to the second operating chamber in the inner chamber, respectively.

[0162] although Figure 7 The end face 28 in the embodiment is located on the side of the bore 26 farthest from the element inlet 6 , but it is not excluded within the scope of the invention that the end face is located on the side of the bore 26 at the inlet 6 .

[0163] Figure 8 A more detailed and specific example of the radially adjustable body 27 is shown.

[0164] The radially adjustable body 27 comprises a fourth shape-variable body 29 which encloses a fourth cavity 30 which is closed or substantially closed with respect to the interior chamber.

[0165] The fourth shape-variable body 29 is configured such that an axial dimension of the fourth shape-variable body 29 according to the rotor shafts 4 a , 4 b is increased or decreased by increasing or decreasing the fourth pressure in the fourth cavity 30 , respectively.

[0166] To this end, the fourth shape-variable body 29 may be provided with a connection point ( Figure 7 or Figure 8 ), for supplying or exhausting the working fluid to increase or decrease the fourth pressure in the fourth cavity 30, respectively.

[0167] By increasing the axial dimension of the fourth shape-variable body 29 relative to rotor shafts 4a, 4b, the fourth shape-variable body 29 increases in the axial direction relative to rotor shafts 4a, 4b toward rotors 3a, 3b. As a result, the axial gap between rotors 3a, 3b and housing 2 relative to rotor shafts 4a, 4b can be sealed, allowing the first operating chamber in the interior chamber to be isolated from the second operating chamber in the interior chamber.

[0168] Once the axial dimension of the fourth shape-variable body 29 relative to the rotor shafts 4a and 4b is reduced again, the fourth shape-variable body 29 of the rotors 3a and 3b is reduced in the axial direction relative to the rotor shafts 4a and 4b. As a result, the axial gap between the rotors 3a and 3b and the housing 2 relative to the rotor shafts 4a and 4b can be reopened, allowing the first operating chamber in the interior chamber to be in fluid communication with the second operating chamber in the interior chamber.

[0169] It is not excluded within the scope of the invention that in the case of an element comprising a plurality of rotors, the gap between the two rotors on the one hand and on the other hand can be sealed or opened by means of the same axially adjustable body.

[0170] Figure 9 A fifth alternative embodiment of an element 1 according to the invention is shown.

[0171] In this fifth embodiment, the inner chamber further comprises a bore 26 according to the orientation of the rotor shafts 4a, 4b.

[0172] exist Figure 9 In the case of the element 1 in , the separate yielding member 10 is embodied as a radially adjustable body 31 attached to a surface of revolution 32 of the bore 26 .

[0173] The radially adjustable body 31 has a second specific deformable shape, which is configured to be able to seal or open the radial gap between the rotors 3a, 3b and the rotating surface 32 according to the rotor shafts 4a, 4b, so that the third operating chamber in the inner chamber can be isolated from or fluidically connected to the fourth operating chamber in the inner chamber, respectively.

[0174] Figure 10 A more detailed and specific example of the radially adjustable body 31 is shown.

[0175] The radially adjustable body 31 comprises a fifth shape-variable entity 33 which encloses a fifth cavity 34 which is closed or substantially closed with respect to the interior chamber.

[0176] The fifth shape-variable body 33 is configured such that a radial dimension of the fifth shape-variable body 33 with respect to the rotor shafts 4 a , 4 b is increased or decreased by increasing or decreasing the fifth pressure in the fifth cavity 34 , respectively.

[0177] To this end, the fifth shape-variable body 33 may be provided with a connection point ( Figure 9 or Figure 10 ), for supplying or exhausting the working fluid to increase or decrease the fifth pressure in the fifth cavity 34, respectively.

[0178] By increasing the radial dimension of fifth shape-variable body 33 relative to rotor shafts 4a, 4b, fifth shape-variable body 33 increases in the radial direction relative to rotor shafts 4a, 4b toward rotors 3a, 3b. Consequently, the radial gap between rotors 3a, 3b and housing 2 relative to rotor shafts 4a, 4b can be sealed, thereby isolating the third operating chamber within the interior from the fourth operating chamber within the interior.

[0179] Once the radial dimension of the fifth shape-variable body 33 relative to the rotor shafts 4a and 4b is reduced again, the fifth shape-variable body 33 of the rotors 3a and 3b is reduced in the radial direction relative to the rotor shafts 4a and 4b. As a result, the radial clearance between the rotors 3a and 3b and the housing 2 relative to the rotor shafts 4a and 4b can be reopened, allowing the third operating chamber in the interior chamber to be fluidically connected to the fourth operating chamber in the interior chamber.

[0180] It is not excluded from the scope of the invention that the element comprises a plurality of rotors, in which case the gap between the rotating surface of the bore on the one hand and the two rotors on the other hand can be sealed or opened by means of the same radially adjustable body.

[0181] Figure 11 A sixth alternative embodiment of an element 1 according to the invention is shown.

[0182] In a sixth alternative embodiment, the housing 2 is provided with yielding members 10 of all the different types described above.

[0183] The element 1 may also comprise mechanical, hydraulic and / or pneumatic means for adjusting the position of each yielding member 10, such as a mechanical actuator or a hydraulic or pneumatic circuit.

[0184] Furthermore, the element 1 may further comprise a controller for driving each yielding member 10 .

[0185] The gap may be controlled when the element 1 is not in operation and / or may be controlled to a predetermined value before the element 1 is put into operation.

[0186] The gap can also be controlled while the element 1 is in operation.

[0187] The control of the gap can be based on the following points:

[0188] - Performance measurement of element 1;

[0189] - vibration measurement; and / or

[0190] - Direct measurement of gaps.

[0191] Of course, it is not excluded within the scope of the invention that the casing 2 is provided with only some of these different types of yielding members 10 .

[0192] It is also not excluded within the scope of the invention that a separate yielding member is combined in an integrated manner with several technical features or functions of the yielding members 10 described previously.

[0193] Furthermore, it is not excluded that element 1 is not a screw compressor element. Other possibilities are, for example, a screw blower element, a screw vacuum pump element, a screw expander element, a tooth compressor element, a tooth blower element, a tooth vacuum pump element, a tooth expander element, a Roots compressor element, a Roots blower element, a Roots vacuum pump element, a Roots expander element, a turbo compressor element, a turbo blower element, a turbo vacuum pump element, or a turbo expander element.

[0194] The invention is not limited to the embodiments described by way of example and shown in the accompanying drawings, but the element for compressing or expanding a gas according to the invention may be realized in various modifications, forms and sizes without exceeding the ambit of the invention defined in the claims.

Claims

1. An element for compressing or expanding gas, comprising: - a rigid housing (2) containing an inner chamber; - a rotor (3a, 3b) located in the inner chamber, the rotor comprising a rotor shaft (4a, 4b); - one or more bearings (7), wherein the rotor shaft (4a, 4b) of the rotor (3a, 3b) is supported by the bearings, and the rotor (3a, 3b) and its rotor shaft (4a, 4b) are rotatably mounted relative to the housing (2) via the bearings (7), wherein the rotors (3a, 3b) are mounted with one or more gaps relative to the wall (5) of the inner chamber, Its characteristics are: The element (1) is provided with a separate yielding member (10), the yielding member comprising: - a fixed portion having a fixed or substantially fixed position relative to the housing (2); and - a position-adjustable portion, the position of which is adjustable relative to the housing (2), the position-adjustable portion being configured to act on at least one gap, The separate yielding member is not directly attached to the rotor (3a, 3b).

2. The element according to claim 1, characterized in that The bearings of the one or more bearings (7) are arranged movably as a whole relative to the housing (2); the position-adjustable portion is configured to contact the non-rotating portion of the bearing that does not rotate relative to the housing (2), and to apply a force on the non-rotating portion so that the bearing as a whole together with the rotors (3a, 3b) are displaced relative to the housing (2).

3. The element according to claim 1 or 2, characterized in that The position-adjustable portion is configured to move inward or outward relative to the at least one gap, respectively, so that the at least one gap is sealed or opened by the position-adjustable portion.

4. The element according to claim 1 or 2, characterized in that The element (1) comprises a plurality of rotors (3a, 3b) which are installed with gaps between them so that a plurality of substantially mutually closed operating chambers are formed in the inner chamber by the rotors (3a, 3b), and The position adjustable portion is configured to change the size of the gap between the rotors.

5. The element according to claim 1 or 2, characterized in that The separate yielding member (10) comprises a radial rotor positioner (11) configured to enable the rotor (3a, 3b) and the housing (2) to be radially displaced relative to each other with respect to the rotor shaft (4a, 4b).

6. The element according to claim 5, characterized in that At least one of the bearings (7) is a radial bearing (8) which is arranged integrally movably relative to the housing (2); and The radial rotor positioner (11) includes a first shape-variable body (12) configured to contact a non-rotating portion of a radial bearing (8) that does not rotate relative to a housing (2) and to apply a force on the non-rotating portion so that the radial bearing (8) as a whole together with the rotors (3a, 3b) are displaced relative to the housing (2).

7. The element according to claim 6, characterized in that The first shape-changing body (12) encloses a plurality of first cavities (14), the first cavities (14) being closed or substantially closed relative to the interior chamber, each first cavity (14) being at a first pressure, wherein, in a plane perpendicular to the rotor axis (4a, 4b), a first one (14a) of the first cavities (14) is located directly opposite at least a second one (14b) of the first cavities (14) relative to the rotor axis (4a, 4b), The first shape-adaptable body (12) is configured such that: when the first pressure in the first one (14a) of the first cavity (14) increases, the volume of the first one (14a) of the first cavity (14) increases and the first pressure in the at least one second one (14b) of the first cavity (14) decreases, so that the volume of the at least one second one (14b) of the first cavity (14) decreases, thereby the rotor shaft (4a, 4b) is displaced toward the at least one second one (14b) of the first cavity (14) in a radial direction relative to the rotor shaft (4a, 4b).

8. The element according to claim 7, characterized in that The radial rotor positioner (11) comprises an outer ring (15), an inner ring (16) and a space between the outer ring (15) and the inner ring (16) which is closed or substantially closed relative to the inner chamber. wherein the outer ring (15) is fixedly attached relative to the housing (2) and the inner ring (16) is fixedly attached to a non-rotating portion of the radial bearing (8) that does not rotate relative to the housing (2), or the inner ring (16) is fixedly attached relative to the housing (2) and the outer ring (15) is fixedly attached to a non-rotating portion of the radial bearing (8) that does not rotate relative to the housing (2), and The radial rotor positioner (11) in the space is provided with a spring structure (17), which is connected to the outer ring (15) on the one hand and to the inner ring (16) on the other hand, so that the space is subdivided into a plurality of mutually closed or substantially closed, approximately ring segment-shaped compartments, each compartment serving as one of the first cavities (14).

9. The element according to claim 1 or 2, characterized in that The separate yielding member (10) includes an axial rotor positioner (18) configured to enable the rotor (3a, 3b) and the housing (2) to be axially displaced relative to each other with respect to the rotor shaft (4a, 4b).

10. The element according to claim 9, characterized in that At least one of the bearings (7) is an axial bearing (9) which is arranged integrally and movably relative to the housing (2); and The axial rotor positioner (18) includes a second shape-variable body (19) configured to contact a non-rotating portion of the axial bearing (9) that does not rotate relative to the housing (2) and exert a force on the non-rotating portion so that the axial bearing (9) as a whole together with the rotors (3a, 3b) are displaced relative to the housing (2).

11. The element according to claim 10, characterized in that The second shape-adaptable body (19) encloses a second cavity (20), the second cavity being closed or substantially closed relative to the interior chamber, the second shape-adaptable body (19) being configured such that an axial dimension of the second shape-adaptable body (19) relative to the rotor shaft (4a, 4b) increases or decreases when a second pressure in the second cavity (20) increases or decreases, respectively.

12. The element according to claim 1 or 2, characterized in that The separate yielding member (10) comprises a radially adjustable ring (21) surrounding the rotor shaft (4a, 4b), The outer periphery (22) of the radially adjustable ring body (21) is fixedly attached relative to the housing (2), and the radially adjustable ring body (21) is configured so that the radial outer inner radius (23) of the radially adjustable ring body (21) can be changed in size depending on the rotor shaft (4a, 4b).

13. The element according to claim 12, characterized in that The radially adjustable ring body (21) comprises an annular third shape-variable body (24) enclosing a third cavity (25) which is closed or substantially closed relative to the inner chamber, the third shape-variable body (24) being configured such that a radially outer inner radius (23) relative to the rotor shaft (4a, 4b) decreases or increases when a third pressure in the third cavity (25) increases or decreases, respectively.

14. The element according to claim 1 or 2, characterized in that The inner chamber includes a bore (26) according to the direction of the rotor shaft (4a, 4b).

15. The element according to claim 14, characterized in that The separate yielding member (10) includes an axially adjustable body (27) attached to an end face (28) of the bore (26), the axially adjustable body (27) having a first specific deformable shape, the first specific deformable shape being configured to be able to seal or open an axial gap between the rotor (3a, 3b) and the end face (28) depending on the rotor shaft (4a, 4b), so that a first operating chamber in the inner chamber can be isolated from or fluidically connected to a second operating chamber in the inner chamber, respectively.

16. The element according to claim 15, characterized in that The axially adjustable body (27) includes a fourth shape-variable body (29) that encloses a fourth cavity (30) that is closed or substantially closed relative to the inner chamber, the fourth shape-variable body (29) being configured such that the fourth shape-variable body (29) increases or decreases in accordance with an axial dimension of the rotor shaft (4a, 4b) when a fourth pressure in the fourth cavity (30) increases or decreases, respectively.

17. The element according to claim 14, characterized in that The separate yielding member (10) includes a radially adjustable body (31) attached to a revolving surface (32) of the bore (26), the radially adjustable body (31) having a second specific deformable shape, the second specific deformable shape being configured to be able to seal or open a radial gap between the rotor (3a, 3b) and the revolving surface (32) depending on the rotor shaft (4a, 4b), so that a third operating chamber in the inner chamber can be isolated from or fluidically connected to a fourth operating chamber in the inner chamber, respectively.

18. The element according to claim 17, characterized in that The radially adjustable body (31) includes a fifth shape-variable body (33) that encloses a fifth cavity (34) that is closed or substantially closed relative to the inner chamber, the fifth shape-variable body (33) being configured such that the fifth shape-variable body (33) increases or decreases in radial dimension relative to the rotor shaft (4a, 4b) when a fifth pressure in the fifth cavity (34) increases or decreases, respectively.

19. The element according to claim 1 or 2, characterized in that The element (1) comprises mechanical, hydraulic and / or pneumatic means for adjusting the position of the position-adjustable portion relative to the housing (2).

20. The element according to claim 1 or 2, characterized in that The element (1) comprises a controller for driving the position-adjustable portion.

21. Device for compressing or expanding a gas, comprising an element (1) according to one of the preceding claims.

22. A separate yielding member (10) for use in an element (1) according to one of the preceding claims 1 to 20 or in an arrangement according to claim 21.

23. A method for controlling an element for compressing or expanding a gas, the element (1) comprising: - a rigid housing (2) containing an inner chamber; - a rotor (3a, 3b) located in the inner chamber, the rotor comprising a rotor shaft (4a, 4b); - one or more bearings (7), wherein the rotor shaft (4a, 4b) of the rotor (3a, 3b) is supported by the bearings, and the rotor (3a, 3b) and its rotor shaft (4a, 4b) are rotatably mounted relative to the housing (2) via the bearings (7), wherein the rotors (3a, 3b) are mounted with one or more gaps relative to the wall (5) of the inner chamber, It is characterized by: The method comprises the steps of acting on at least one gap by adjusting the position of a position-adjustable portion of a separate yielding member (10) of the element (1) relative to the housing (2), wherein the fixed portion of the individual yielding member (10) is maintained in a fixed or substantially fixed position relative to the housing (2), and Therein, the separate yielding member (10) is not directly attached to the rotor (3a, 3b).

24. The method according to claim 23, wherein The bearings of the one or more bearings (7) are arranged movably as a whole relative to the housing (2); when acting on at least one gap, the position-adjustable portion contacts the non-rotating portion of the bearing that does not rotate relative to the housing (2), and exerts a force on the non-rotating portion so that the bearing as a whole, together with the rotors (3a, 3b), is displaced relative to the housing (2).

25. The method according to claim 23 or 24, characterized in that The position-adjustable portion is respectively moved inward or outward relative to the at least one gap, so that the at least one gap is sealed or opened by the position-adjustable portion.

26. The method according to claim 23 or 24, characterized in that The element (1) comprises a plurality of rotors (3a, 3b) which are mounted with gaps between them so that one or more substantially mutually closed operating chambers are formed in the inner chamber by the rotors (3a, 3b), and The method comprises the following steps: changing the size of the gap between the rotors by adjusting the position of the position-adjustable portion relative to the housing (2).

27. The method according to claim 23 or 24, characterized in that At least one gap is controlled when the element (1) is not in operation, and / or at least one gap is controlled to a predetermined value before the element (1) is put into operation.

28. The method according to claim 23 or 24, characterized in that At least one gap is controlled when the element (1) is in operation.

29. The method according to claim 23 or 24, characterized in that The position of the position-adjustable portion relative to the housing (2) is adjusted mechanically, hydraulically and / or pneumatically.

Images